Fuse switch



June 12, 1934. T BlRKENMAlER 1,962,922

FUSE SWITCH Filed Oct. 23, 1933 3 Sheets-Sheet l FIG. .I.

l /23 12/ 4 I60- a /6/L: l7

June 12, 1934. T BIRKENMAIER 1,962,922

FUSE SWITCH Filed Oct. 23, 1933 3 Sheets-Sheet 2 June 12, 1934.glRKENMAlER 1,962,922

FUSE SWITCH Filed Oct. 23, 1933 I (5 Sheets-Sheet 5 Patented June 12,1934 UNITED STATES ruse swrrcn Theodore Birkenmaier, St. Louis, Mo.,assignor to W. N. Matthews Corporation, St. Louis, Mo., a corporationofMissouri Applicationpctober 23; 1933, Serial No. 694,169

. Claims. (01. 200126) This invention relates to fuse switches, and withregard to certain more specific features, to delayed action, reclosingfuse switches. v

The invention is an improvement upon the 5 structure shown in PittmanUnited States Patent 1,894,056, dated January 10, 1933, and the UnitedStates Patent 1,940,575 of Lester Pierce Boll, dated December 19, 1933,for Fuse.

Among the several objects of the invention may be noted the provision ofimproved, automatically reclosing fuse switches of the class shown insaid patent and patent application which shall have time-delayedreclosing features; the provision of apparatus of the class described inwhich the time delay may be adjusted, and which is automatically placedin operating con dition' by the normal operation of forcing a fusecartridge into circuit closing position; the provision of apparatus ofthis class in which the sequence of fuse closures and periods of timedelay are so arranged that a temporarily-im-. paired line may berestored to operation, both when the trouble clears quickly, and when itclears slowly, maximum speed of closure being effected under allconditions usually required to be met; and the provision of' apparatusof the class described which shall be thoroughly reliable andeconomical. Other objects will be in part obvious and in part pointedout hereinafter.

The invention accordingly comprises theelements and combinations ofelements, features of construction, and arrangements of parts which willbe exemplified in the structures hereinafter described, and the scope ofthe application 'of which will be indicated in the following claims.

In the accompanying drawings, in which is illustrated one of variouspossible embodiments of the invention,

Fig. l is a side elevation of the switch;

Fig. 2 is a front elevation;

Fig. -3 is a fragmentary, enlarged, front elevation of the lower end ofthe switch, parts being broken away to show a time delay mechanism; Fig.4 is a vertical section taken on line 44 of Fig. 3; I

Fig. 5 is a vertical section taken on line 5--5 of Fig. 3;

Fig. 6 is a fragmentary detail of an adjustable H cam mechanism, being.taken substantially on line 66 of Fig. 5;

Fig. 7 is a view sim lar t0 Fig. 6 showing an alternate posit-ion; I Y

, Fig. 8 is a fragmentary side elevation showing 53 the invertedapplication of a fuse cartridge, the

g iew being taken substantially on line 8-8 of Fig. 9 is a fragmentarydetailof a cartridge head; and,

Fig. 10 is a vertical section taken on line 10-10, of Fig. 3. 7

Similar reference characters indicate corresponding parts throughout theseveral views of the drawings. I

A large proportion of fuse outages on power circuits are caused by suchthings as lightning. transients which last of the order of one-half toone cycle, or temporary short circuits of somewhat longer duration suchas wires temporarily swinging together, tree limbsand animals or thelike touching two wires but being soon burned off, and like troubles,which may last from a few cycles to a few seconds or a few moments.

With reclosing switches functioning serially and all closing promptly,the temporary trouble 5 may last long enough to cause aheclosure' ofseveral switches and associated blowing of fuses before the troubleclears. In fact, all of a given bank of fuses may be blown in sequencebefore the trouble clears, thus impairing the usefulness of the switch.I Y

With this invention, if the trouble is quite transient, such as alightning transient, a quick reclosure is available which avoids undueincon- 'venience to the current consumer; whereas if the temporarytrouble is of a longer duration, there is also available a slowerreclosure which encompasses the time required for effecting. clearing ofthe trouble. Furthermore, the slow reclosure is made adjustable so as tosuit various expected conditions 'of operations so that if the slowclearing troubles are on the average of a few seconds in clearing, thetime for clearing can be encompassed by the reclosure time, and if theaverage clearing is of a longer duration, the time of reclosure can belengthened to encompass the same. Thus, in a single switch clearing maybe effected of troubles which require VQEOHS periods for clearing. Atthe same time thi invention avoids w the complications or oil switchesand thehigh m cost of these. I

Referring now more particdlarly to the drawings, there is shown atnumeral 1 an insulator rack supporting insulators 3, the latter carryingupper and lower brackets 5 and 7 respectively.

' A line wire connection 9 is provided on the upper bracket 5 and a linewire connection 11 on the lower bracket '1. The upper bracket5carrlescentrally located spring terminal clips 13 forspringeng'age'ment with the flat sides of an upper terminal contact 1'7of a central fuse cartridge 6. Zhe lower bracket '7 carries a contactportion for engagement with lower trunnions 19 of a lower contact 20 ofthe cartridge (3. This cartridge C is of a general nature of thecartridge described in the United States Patent 1,935,385 of TheodoreBirkenmaier, dated November l l, 1933, for Fuse, and has a connection 2iin the upper contact l! for a fuse link 23 which passes downwardlythrough an insulating tube 25 of said cartridge C and emerges from thelower end thereof. The insulated tube 25 passes through the lowercontact 20.

Exteriorly, the fuse link 23 passes under and over a hinged element 29of a clamp 22'", a leaf spring element 31 forming the other element or"the clamp as described in said Birkenmaier patent.

When the link 23 is loaded, the spring is pulled down hom theuntensioned, dotte line position 32 shown in Fig. and the clamp T isopened by rotating the member 29 counter clockwise and thereafter feding in the end of the link 23. Then upon release of the link from thehand of the operator, the strained position is as sumed as showi solidlines in Figs, 1 and 5. The spring 81' :iorces down the element 29, thusclosing the clamp 2'? to hold the link 23 in strained position in thetube. Th se points will be clear from Figs. 1 to .2 and 8, and from saidBirken c upper end he to platen 33 which is d'to tact and whic "snormally press d upwardly by a leaf spring reacting against the contact25.

Said lower contact 25 carries said trunnions 19 which res tact l5. 'lnesockets 3i being open at the top, provision is thereby made for applyingand removing as a whole the central fuse cartridge As may be seen from15, the fused cartridge C may be applied to the sockets 3'7 by invertingthe cartridge C. The trunnions 19 rest in the sockets 3'! and thecartridge C is then rotated counterclockwise as indicated by the arrow.This swings the upper contact 1'? into the spring clips 13.

Referring now to the upperterminal 1'7 oi the cartridge C, shown in Fig.it will be seen to include ears for pivotally supporting a bell crank4'7, the latter having a latcharm 49 and a pressure arm 51, the pressurearm being en gaged by either corner 53 or 55 of a rocker 5'7 having anoperating ring 59. A coil spring 61' reacting between the upper terminal1'7 and the arm 51 of the bell crank 4'? tends to normally throw thelatch 49 into upward position. However, a hook of a linemans extensiontool or the like is applied to the ring 59, either upward or downwardpressure (in fact any pressure except one directed into the axis ofrotation of the member 5'7) will cause either one of the corners 53 or55 to press the arm 51 of the bell crank 4'7, thus causing the latch 49to be depressed against the reaction of said spring 61.

The cartridge C as well as identical cartridges L and to be referred to)may be provided with the fuse link 23, the same being tensioned by thespring 31 while the cartridge as a whole is separated from the terminals18 and 15. Thus loaded, the cartridge C may have the trunnions 19applied to the fixed sockets 37, the whole cartridge then bein rotatedto'the position shown escapee in Fig. 1, the upper terminal 1'7 engagingth upper line terminal 13.

The lower bracket '7 also carries sidewardly located sets of ears 63which support sockets 65 for receiving the trunnions 19 of rightandleft-hand cartridges R, and L respectively, said cartridges R and Lbeing substantially duplicates of said central cartridge C.

The cartridges R and L are normally pressed clockwise by means ofplungers '70 held in bearings '72 and normally pressed forward by coilsprings '71. By this means the counterclockwise rotation of eithercartridge L or R is effected against the. reactions of springs '71 andtherefore the cartridges are at all times tensioned to spring from thevertical position shown in Fig. l to the sloping, connected positionsparallel to the central cartridge C. They are prevented from swingingclockwise (until released) by means of dogs '73. The dog 73 on the leithand cartridge L swings under a latch '25 which is fastened to a sleeveV6. The sleeve 76 is mounted on a corresponding shaft '78. The mechanismby means of which blowing oi the central cartridge C releases the latch'75 to cause the leit-hand'cartridge L to spring into circuit-closingposition will be dc scribed later.

The right hand cartridge it carries a similar dog 73 which when thecartridge is rotated countercloc qwise into vertical position passesunder a similar latch '75 carried on the rod 78.

From the above it may be seen that both the right and left handcartridges R and L are applied in the manner shown in Fig. 8 and movedcounterclockwise against spring-pressed rams such as shown at '70 so asto place the dogs '73 under the latches 75, one latch being carried onthe rod '78 and the other on the sleeve '75. Fig. 4 shows a latchedarrangement and Fig. 8 shows an unlatched arrangement.

As shown in Fig. 1, no upper terminal spring clips are provided for thecartridges R and L in their vertical positions but such are provided atthe ends of a T head 80 in a forward plane with the central spring clip13. numbered 81 and 83 for therespective cartridges L and R. Associatedwith the respective clips are edges 93 which are adapted to be engagedby the ends of the arms 49 upon forward swing of the cartridges R and L(Fig. 1). It will be understood that the central cartridge 0 cannot passbeyond the sloping position shown in Figs. 1, 2, and 3, the sameengaging a stop 82 to prevent this as it is applied. On the other hand,

the cartridges L and R have no corresponding LO the purpose herein tohave all of the cartridges These clips are substantially identical andfused as described in connection with cartridge C. The cartridge C isthen invertedly applied to the lower contact 15 and rotatedcounterclockwise to the Fig. 1

position, thereby closing the circuit. Next, a right or left-handreserve cartridge is likewise applied and rotated through its contacts81 or 88 as the case may be, to the vertical position. Both right andleft hand cartridges are thus treated. Their temporary passage throughthe circuit closing positions does not change the circuit conditions,because the central fuse has closed the circuit. As in said patent, itis the intention herein to have blowing of the central fuse cartridge Ceffect release of the left hand cartridge so that it 'may spring intocircuit closing position and so that subsequent blowing of the left-handcartridge shall release the righthand cartridge so that it may assume acircuit closing position. However, it is desired to avoid thedisadvantage of all reserve cartridges recl'osing instantaneously. Forthis reason time delay scribed in detail. It comprises a housing 95attachedto the lowerbracket93. This housing 95 contains an escapementmechanism 97. This mechanism comprises an escapement wheel 99cooperating with an escapement yoke' 101, theyoke 101 reciprocatingunder alternate impulses of opposite teeth on the wheel 99 so as todetermine the rate at which the wheel 99 rotates. The wheel 99 is drivenby means of a pawl mechanism 103 cooperating with a ratchet 102 fastenedto said wheel 99, the ratchet 102 and wheel 99 being loose (as a unit)on the shaft 105. The pawl mechanism 103 is fastpn the shaft 105. Theshaft 105 carries a pinion 107 which is driven by gear 109 carried on acountershaft lll'with a pinion 113, the latter being meshed with a mainsegmental gear 114. A drivespring 115 reacts between the case 95 and thesegmental gear 114. It will be seen that if the segmental gear 114 isrotated counterclockwise (Fig. 4) clockwise (Fig. 5) soas to wind thespring 115,.thegear train will move so as to move the pawl mechanism 103coun-' terclockwise over the teeth of the ratchet 102. When the windingaction ceases, the spring reacts to drive the pawl mechanism 103clockwise so asto drive the ratchet wheel 102 and the escapement wheel99. The reciprocation of the yoke 101 determines the rate at which thegear when the respective cartridge is in its upper positrain shall rundown.

In order to transmit the action due to running down torelease the nextcartridge, each segmental gear 114 .is provided with a socket 117 which,as the gear 114 rotates clockwise, in due course contacts with the lowerend 119 of a push rod 121 which is connected with a crank 123, thelatter being attached to the rod 73 in the case of the time delaymechanism 93 and to the sleeve 76 operable from the time delay mechanism91. Thus it will be seen that the time delay mechanism 91 controlsrelease of the latch 75 for releasing the lefthand cartridge L; whereasthe time delay mecha-' nism 93 controls the release of the other latch75 for releasing the right hand cartridge R.

Winding of the spring 115 is accomplished by means of the rotation ofthe respective cartridge into its upper position- To accomplish thiseach cartridge is provided withv a dog 125 which, incidentally, isprovided with an extension 127 to give support for the fuse clamp 29.The function of the dog 125 in the present connection is to contact withthe lip 129 of a barrel cam 131, the latter being borne on an extensionjournal 133 within a hollow hub 135 of the gear 114. The cam 131 islaterally slidable on said stud 133 and is spring-pressed toward itsrespective cartridge by a spring 137 (Figs. 6 and 7). It is not splineddirectly to the stud 133 but is made adjustable in positionwith respectto'the gear 114 by means of a finger 139 held in a slot 141 in said cam131. The finger 139 constitutes part of a lever 143 which may beadjusted. The end of the lever is .onds and/ or minutes.

provided with a locking not 145 swinging in a calibrated groove 147 ofthe gear 114. The groove may be calibrated in terms of cycles and/orsecresponding cartridge into upward position results in contact betweenthe respective dog 125 and lip 129 of the respective barrel cam 131. Thebarrel Thus movement of a corcam 131 is fixed with respect to the gear114 by the adjustable connection consisting of slot 141, finger 139,lever 143 andlock nut 145. The initial relationship between the edge 129of the barrel cam 131 and the dog 125 may beadjusted by adjusting thelever 143, thus either advancing. or

delaying the contact between dog 125 and the shortening the time itrequires for the socket 117 to cause lifting of the rod 121 and releaseof the corresponding latch 75. Thus, the time delay is accomplished byso relating the barrel cam 131 to the gear 114 which carries the pocket117 so that the pocket 117 is moved more or less when the respectivecartridge is thrown into its upward position. The movement of the pocket117 is proportional to the winding movement applied to the escapementand thus the escapement runs alonger or shorter time at a constant ratein proportion to the amount that the pocket 117 has moved downwardly.Thus the rate of release is the same but the total time required isdifferent according to the adjustmentof the lever 143.

In order that,the escapement mechanism may .be held in woundpositiomuniil the respective fuse blows, the barrel cam 131 is madelaterally movable on the stud 1 33 and on the finger 139 and it isprovided with a rearward camming surface 149 which, upon moving therespective cartridge up (with winding of the spring 115) con-' tactswith a fixed portion 151 of the respective housing 95. The .surface 149and fixed member 151 by said adjustment become related so that -andnisadapfed to be engaged by a tongue 159 of the respective platen 33 whenthe platen moves up as the spring 31 is released upon blowing of therespective fuse.

In the case of the left-hand fuse L which goes to a vertical positionfirst and then springs forward to circuit closing position, isrespective release arm 155 in mechanism 93 is provided with a springyfinger 161 over which rides the platen extension 160 upon upwardmovement of cartridge L., When the cartridge L returns to circuitclosing position the extension. 169 positions ilself under the finger161. The reason for this will appear.

The operat'i on is as follows: Three identical cartridges are loaded,placing the springs 31 asshown in Fig. 8. Their trunnions 19 are appliedto the respective sockets after The latch 153 is normally pressed to rundown under the C is then forced up into its upper sloping, circuitclosing position, shown in Fig. 1, thereby closing the circuit betweenthe line contacts 9 and 11. This central. cartridge does not leave thisposition until the line man again removes it for-reloading after it isblown.

Next, the other two cartridges are successively pushed up through theirrespective upper contacts 81 and 83 to the vertical positions shown inFigs. 1 to 1. They are held vertically by the latches 75. During themovement of the cartridges C and L to their upward positions, the timedelay mechanisms have been tensioned and presumably said mechanisms havepreviously been adjusted for the desired time delay in reclosing therespective cartridges which they control. The barrel cams 131 are drawnout of engagement with the dogs 125 on the cartridges by the engagementof cam'surfaces 149 with the fixed stops 151 (see Figs. 6 and 'l)Assuming that the device is set for taking care of short transients andshort circuits of longer duration, it will be seen that the time delaymechanism 91 will'be set for a reclosure after perhaps only a few cyclesof outage; whereas the time delay mechanism 93 will be set for reclosureafter a more substantial period of time. Thus, assuming that thecartridge C blows, its platen 33 will whip upwardly to pull out and dropthe fuse linlr and to raise the respective arm 155 and thus, through thelatch 153, release the barrel cam 131, which being attached to thesegmental gear 114 permits the escapement mechanism to tension of thespring and the socket 117 to move the stem 121 upwardly to open .thelatch associated with the lefthand cartridge L. This cartridge thus,almost immediately, springs forward under pressure of its ram '70 tocircuit closing position in the upper spring contacts 81, therebyreclosing the circuit. It will be understood that the time delay may bemade longer if desired by adjusting the mechanism 91 at nut 145.

Then, assuming that instead of being a transient outage, the time issomewhat longer. This will also cause blowing of the reclosed left-handcartridge L and it will, in like manner, set off the time delaymechanism 93 which upon running down unlatches the latch 75 associatedwith the right-hand cartridge R, thus springing the cartridge Rinto itscircuit closing position.

It is preferable that the time delay mechanisms which operate first havethe shortest time delay adjustment so that if a transient occurs, aminimum number of reclosures or a single one will take care of it.

It will be further understood that in a set of three cartridges, asherein disclosed, the time delay mechanism 91 could be eliminated and aninstantaneous reclosure be made with the left hand cartridge L, as inthe case of said Patent 1,894,056. The normal mechanical delay wouldtake care of transients. Then the time delay mechanism 93 betweencartridges L and R would be set for a longer reclosure period to takecare of temporary short circuits and the like.

It is to be further understood that any number of cartridges may be usedin a bank with time delay mechanisms serially arranged between them.Thus each successive time delay mechanism could be set to take care ofincreasingly longer outages. The particular number will depend uponcircumstances and the expense'involved. Simplification may of course beeffected by operating several fuses from one time delay mechanism whichwould be permitted to run down a fractional distance for each byproperly located hold ing latches associated with the respectivecartridges.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructionswithout departing from the scope of the invention, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense. a

1 claim:

1. A fuse switch comprising at least two pairs of line terminals, atleast two fuse cartridges, means for moving one of said cartridges tocircuit closing position, means for moving the other cartridge to anopen circuit position, means for tensioning said other cartridge tonormally press the same to closed circuit position, a latch forresisting movement to circuit closing position, a time delay mechanism,spring means for operating the time delay mechanism, an escape- A mentfor determining the rate of operation of the time delay mechanism, meansfor tensioning said spring upon applying the circuit closing car"tridge, means holding the time delay mechanism in tension while thecircuit closing fuse cartridge is unblown, and means responsive to theblowing or" said circuit closing cartridge to release the time delaymechanism for operation, and means whereby predetermined movement of thetime delay mechanism releases said latch to effect movement of the opencircuit cartridge to closed circuit position.

2. A iuse switch comprising at least two pairs of line terminals, atleast two fuse cartridges, means for moving one of said cartridges tocircuit closing position, means for moving the other cartridge to anopen circuit position, means for tensioning said other cartridge tonormally press the same to closed circuit position, a latch forresisting movement to circuit closing position, time delay mechanism,spring means for operating the time delay mechanism. an escapement fordetermining the rate of operation of the time delay mechanism,connective means for tcnsioning said spring upon applying the circuitclosing cartridge, means opening the connection between the circuitclosing cartridge and its respective tensioned time delay mechanism andfor holding the time delay mechanism in tension while the circuitclosingiuse cartridge is unblown, and means responsive to the blowing ofsaid cartridge to release the time delay mecha--.

nism for operation, and means whereby predetermined movement of the timedelay mechanism releases said latch to effect movement of the open.circuit cartridge to closed circuit position.

3. A. fuse switch comprising at least two pairs of line terminals, atleast two i'use cartridges, means for moving one of said cartridges tocircuit closing position, means for moving the other cartridge to anopen circuit position, means for tensioning said other cartridge tonormally press the same to closed circuit position, a latch forresisting movement to circuit closing position, a time delay mechanism,spring means for operating the time delay mechanism, an escapement fordetermining the rate of operation of the time delay mechanism, meainsfor tensioning said spring upon applying the circuit closing cartridge,means holding the time delay mechanism in tenmenses sion while thecircuit closing fuse cartridge is ieases its respective iatch to effectmovement of unhlown, means responsve to the blowing of said the otheropen-circuit cartridge to dosed-circuit cartridge to release the timedelay mechanism position, for operation, means whereby predetermined 5.A fuse switch comprising at least three pairs 5 movement of the timedelay mechanism reieases of line contacts, at ieast three similar ruseear saidiatch to effect movement of the open circuit tridges adapted toeiectricaiiy connect the recartridge to closed circuit position, andmeans spective pairs of contacts, means for moving one for adjusting theamount of tensioning effected of said cartridges to circuit-closingposition, by said movement of the closed circuit cartridge means formoving the other cartridges to open n whereby the period of time delayin activating circuit positions, means for tensioning said other theopen circuit cartridge is made adjustable. cartridges to normally pressthe same to closed 4. A fuse switch comprising at least three pairscircuit positions, latches for resisting their moveof line contacts, atleast three similar fuse carments to oircuit-ciosing positions, ieasttwo tridges adapted to electricaily connect the respectime-delaymechanisms, spring means i'or opentive pairs of contacts, means formoving one of ating the respective time-delay mechanisms, eo saidcartridges to circuit-closing position, means capements for determiningthe rates at operation. for moving the other cartridges to open-circuitoi the timedeiay mechanisms, means for tensionpositions, means fortensioning said other car ing the respective springs upon applying there tridges to normally press the same to closed spectivecircnit-ciosing: cartridges, means he m circuit positions, latches forresistingtheir moveing the 'tiine deiay mechanisms in tension while asments to circuit-closing positions, at least two the eironit-ciosinginse cartridge is unhiown, time-delay mechanisms, spring means for opermeans responsive to the hiowing of said cartridge ating the respectivetime-delay mechanisms, to release one tirnchcia Y mechanism foroperaescapements for determining the rates oi opertion, means wherebypredetermined movement oi? ation oi the time-delay mechanisms, means theiast-named tiznmdelay mechanism reieases 100; for tensioning therespective springs upon an the respective latch to eliect movement ofthe replying the respective circuit-closing cartridges, spectiveopen-circuit cartridge to its clesed-cir means holding the time-delaymechanisms in cuit position, means associated with said lasttensionwhile the circuit-closing fuse can named cartridge responsive to theblowing oi the tridge is unblown, means responsive to the blowsameadapted to reiease the other time-delay m5 ing of said cartridge torelease one timemechanism for operation, means whereby predelaymechanism for operation, means whereby determined movement of said othertime-delay predetermined movement of the last-named mechanism releasesits respective latch to effect time-delay "mechanism releases therespective movement of the other open-circuit cartridge to latch toeffect movement of the respective open-- closed-circuit position, andmeans for adjusting 1m circuit cartridge to its closed-circuit position,the respectivetensionings effected by movements means associated withsaid last-named cartridge of the respective closed-circuit cartridges,whereresponsive to the blowing of the same adapted to by the periods oftime-delay in actuating the release the other time-delay mechanism foroperopen-circuit cartridges are madeindividually ad- 40 ation, andmeanswhereby predetermined movejustahle. 5

ment of said other time-delay mechanism re- THEODORE to 12a

